A top official of the company also said that no difference in neutralisation was observed between B.1.1.7 (first isolated in the UK) and vaccine strain (D614G) that was used to develop Covaxin.
Citing a study published in peer-reviewed medical journal Clinical Infectious Diseases, Bharat Biotech joint managing director Suchitra Ella tweeted: “A modest reduction in neutralisation by a factor of 1.95 was observed against B.1.617 variant compared to the vaccine variant (D614G). Despite this reduction, neutralising titre levels with B.1.617 remain above levels expected to be protective.”
“Covaxin gets international recognition yet again, by scientific research data published demonstrating protection against the new variants. Yet another feather in its cap,” she tweeted early on Sunday.
The study, `Neutralisation of variant under investigation B.1.617 with sera of BBV152 vaccinees’, was covered in the May 7 issue of the journal that is published by the Oxford University Press.
The study found that the “B.1.617 variant performance with vaccine sera was better than recovered cases. The result of B.1.1.7 variant neutralization with BBV152 vaccine sera and findings of B.1.617 emphasize that this vaccine is robust against emerging mutation and maintains the efficacy of the vaccine,” the paper said.
As part of the study, researchers from Bharat Biotech and Indian Council of Medical Research-National Institute of Virology (ICMR-NIV) took the sera of 28 volunteers vaccinated with Covaxin in the Phase II clinical trials and compared its ability to effectively neutralise the B.1.617 variant as compared to the D614G strain and B.1.1.7 variant.
This was done by collecting sera samples from 17 patients that had recovered after being infected with lineage B.1.1.1, B.1.351, B.188.8.131.52 and D614G of SARS-CoV-2.
These samples were then used to perform PRNT50 (Plaque reduction neutralisation test) test against the B.1.617 variants and results were compared with the sera samples of the Covaxin recipients.